Sailing performance may be maximized by adjusting the position of the mast step linearly along a sail-driven vehicle, particularly a sail board.
Shifting the mast step is useful when changing directions of travel and relative wind.
Adjusting the mast step adjusts the center of application of force from the mast to the craft. Repositioning the mast step is desirable when changing the sailed course from running before the wind to close-hauled courses or variations of angles of attack therebetween.
Adjusting the mast step may be useful in varying conditions of apparent wind velocity.
It is highly desirable to be able to change the mast step while underway and with minimum efforts or unusual movements.